Raman spectroscopy and field emission characterization of delafossite CuFeO2
Raman spectroscopy and field emission characterization of delafossite CuFeO2
复制标题
DOI：
10.1063/1.3284160
复制
发表时间：
2010-01
影响因子：
3.2
通讯作者：
S. Pavunny;Ashok Kumar;R. Katiyar
中科院分区：
文献类型：
--
作者：
S. Pavunny;Ashok Kumar;R. Katiyar
采用改进的固相反应技术合成了铜铁矿p型CuFeO 2（CFO）半导体，并通过X射线衍射、X射线光电子能谱（XPS）、X射线能量色散谱和扫描电子显微镜对其进行了研究，揭示了CFO的单相性质，Cu/Fe原子比为1：1。通过XPS分析了CFO的价态，表明Cu和Fe离子处于高自旋S=5/2的+1价和+3价态。“开启场”是获得9 nA的发射电流所需的宏观场，计算为5.72V/μm。CFO的室温拉曼光谱在Eg = 351 cm-1和Ag = 692 cm-1处显示出两个主要的拉曼激活模，与其他铜铁矿结构的雅阁谱一致。温度依赖的拉曼光谱表明，这两个模式移动到较低的频率与强度显着下降，随着温度的升高。两条声子线的频移和线宽与基于该模型的阻尼谐振子理论模型吻合较好。
Delafossite p-type CuFeO2 (CFO) semiconductors were synthesized by a modified solid state reaction technique and investigated by x-ray diffraction, x-ray photoemission spectroscopy (XPS), energy dispersive x-ray spectroscopy, and scanning electron microscopy, revealing the single-phase nature of CFO with 1:1 Cu/Fe atomic ratio. The valance states of CFO were examined by XPS and suggest Cu and Fe ions are in +1 and +3 valance states with high spin S=5/2. The “turn-on field” which is the macroscopic field needed to get an emission current of 9 nA, was calculated as 5.72 V/μm. Room temperature Raman spectra of CFO displayed two main Raman active modes at Eg∼351 cm−1 and Ag∼692 cm−1 in accord with other delafossite structures. Temperature dependent Raman spectra showed that both the modes shifted to lower frequency with significant decrease in intensity with increase in temperature. Frequency shift and linewidth of both phonon lines matched well with the theoretical damped harmonic oscillator model based on t...